Apache Airflow - trigger/schedule DAG rerun on completion (File Sensor) - triggers

Question

Good Morning.
I'm trying to setup a DAG too
Watch/sense for a file to hit a network folder
Process the file
Archive the file
Using the tutorials online and stackoverflow I have been able to come up with the following DAG and Operator that successfully achieves the objectives, however I would like the DAG to be rescheduled or rerun on completion so it starts watching/sensing for another file.
I attempted to set a variable max_active_runs:1 and then a schedule_interval: timedelta(seconds=5) this yes reschedules the DAG but starts queuing task and locks the file.
Any ideas welcome on how I could rerun the DAG after the archive_task?
Thanks
DAG CODE
from airflow import DAG
from airflow.operators import PythonOperator, OmegaFileSensor, ArchiveFileOperator
from datetime import datetime, timedelta
from airflow.models import Variable
default_args = {
'owner': 'glsam',
'depends_on_past': False,
'start_date': datetime.now(),
'provide_context': True,
'retries': 100,
'retry_delay': timedelta(seconds=30),
'max_active_runs': 1,
'schedule_interval': timedelta(seconds=5),
}
dag = DAG('test_sensing_for_a_file', default_args=default_args)
filepath = Variable.get("soucePath_Test")
filepattern = Variable.get("filePattern_Test")
archivepath = Variable.get("archivePath_Test")
sensor_task = OmegaFileSensor(
task_id='file_sensor_task',
filepath=filepath,
filepattern=filepattern,
poke_interval=3,
dag=dag)
def process_file(**context):
file_to_process = context['task_instance'].xcom_pull(
key='file_name', task_ids='file_sensor_task')
file = open(filepath + file_to_process, 'w')
file.write('This is a test\n')
file.write('of processing the file')
file.close()
proccess_task = PythonOperator(
task_id='process_the_file',
python_callable=process_file,
provide_context=True,
dag=dag
)
archive_task = ArchiveFileOperator(
task_id='archive_file',
filepath=filepath,
archivepath=archivepath,
dag=dag)
sensor_task >> proccess_task >> archive_task
FILE SENSOR OPERATOR
import os
import re
from datetime import datetime
from airflow.models import BaseOperator
from airflow.plugins_manager import AirflowPlugin
from airflow.utils.decorators import apply_defaults
from airflow.operators.sensors import BaseSensorOperator
class ArchiveFileOperator(BaseOperator):
#apply_defaults
def __init__(self, filepath, archivepath, *args, **kwargs):
super(ArchiveFileOperator, self).__init__(*args, **kwargs)
self.filepath = filepath
self.archivepath = archivepath
def execute(self, context):
file_name = context['task_instance'].xcom_pull(
'file_sensor_task', key='file_name')
os.rename(self.filepath + file_name, self.archivepath + file_name)
class OmegaFileSensor(BaseSensorOperator):
#apply_defaults
def __init__(self, filepath, filepattern, *args, **kwargs):
super(OmegaFileSensor, self).__init__(*args, **kwargs)
self.filepath = filepath
self.filepattern = filepattern
def poke(self, context):
full_path = self.filepath
file_pattern = re.compile(self.filepattern)
directory = os.listdir(full_path)
for files in directory:
if re.match(file_pattern, files):
context['task_instance'].xcom_push('file_name', files)
return True
return False
class OmegaPlugin(AirflowPlugin):
name = "omega_plugin"
operators = [OmegaFileSensor, ArchiveFileOperator]

Answer 1

Dmitris method worked perfectly.
I also found in my reading setting schedule_interval=None and then using the TriggerDagRunOperator worked equally as well
trigger = TriggerDagRunOperator(
task_id='trigger_dag_RBCPV99_rerun',
trigger_dag_id="RBCPV99_v2",
dag=dag)
sensor_task >> proccess_task >> archive_task >> trigger

Answer 2

Set schedule_interval=None and use airflow trigger_dag command from BashOperator to launch next execution at the completion of the previous one.
trigger_next = BashOperator(task_id="trigger_next",
bash_command="airflow trigger_dag 'your_dag_id'", dag=dag)
sensor_task >> proccess_task >> archive_task >> trigger_next
You can start your first run manually with the same airflow trigger_dag command and then trigger_next task will automatically trigger the next one. We use this in production for many months now and and it runs perfectly.